During the course of the host's immune response to the GAS, the host's antigens may, as a result of this molecular mimicry, be mistaken as foreign; this leads to an inflammatory cascade with resultant tissue damage. In patients with ARF with Sydenham chorea, common antibodies to antigens found in the S pyogenes cell membrane and the caudate nucleus of the brain are present, further supporting the concept of an aberrant autoimmune response in the development of ARF.
Interest in whether such autoimmune responses play a role in the pathogenesis of the syndrome known as pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS) has been considerable, although further work is necessary to establish the link between streptococcal infections and these syndromes.
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Invasive soft tissue infection due to Streptococcus pyogenes. This child developed fever and soft-tissue swelling on the fifth day of a varicella-zoster infection. Leading edge aspirate of cellulitis grew S pyogenes. Although the patient responded to intravenous penicillin and clindamycin, operative débridement was necessary because of clinical suspicion of early necrotizing fasciitis.
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Streptococcus group A infections. Beta hemolysis is demonstrated on blood agar media.
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Streptococcus group A infections. M protein.
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Streptococcus group A infections. Erysipelas is a group A streptococcal infection of skin and subcutaneous tissue.
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Streptococcus group A infections. White strawberry tongue observed in streptococcal pharyngitis. Image courtesy of J. Bashera.
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Streptococcus group A infections. Streptococcal rash. Image courtesy of J. Bashera.
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Group A Streptococcus on Gram stain of blood isolated from a patient who developed toxic shock syndrome.
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Streptococcus group A infections. Necrotizing fasciitis of the left hand in a patient who had severe pain in the affected area.
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Streptococcus group A infections. Patient who had had necrotizing fasciitis of the left hand and severe pain in the affected area (from Image 8). This photo was taken at a later date, and the wound is healing. The patient required skin grafting.
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Streptococcus group A infections. Gangrenous streptococcal cellulitis in a patient with diabetes.
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Erythema secondary to group A streptococcal cellulitis.
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Invasive soft tissue infection due to Streptococcus pyogenes. This child developed fever and soft-tissue swelling on the fifth day of a varicella-zoster infection. Leading edge aspirate of cellulitis grew S pyogenes. Although the patient responded to intravenous penicillin and clindamycin, operative débridement was necessary because of clinical suspicion of early necrotizing fasciitis.
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Streptococcus group A infections. Necrotizing fasciitis rapidly progresses from erythema to bullae formation and necrosis of skin and subcutaneous tissue.
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Throat swab. Video courtesy of Therese Canares, MD; Marleny Franco, MD; and Jonathan Valente, MD (Rhode Island Hospital, Brown University).
